Obsidian Blog

Diagnosing Low T: A Strategic Approach

As a urologist who has focused on men’s health for more than a decade, I often treat testosterone-deficiency syndrome — TDS or, colloquially, “Low T.” Seemingly straightforward, it’s one of the most misunderstood, mismanaged medical conditions; diagnosing and treating it is an art form requiring specialized training, excellent communication skills, diagnostic acumen and strategic planning.

My background is different: In college, I double-majored in chemistry and molecular biology, learning about hormone structure and function at the cellular and molecular level. Four years of medical school followed, after which I spent five intensive years immersed in a urologic residency studying under Dr. Culley C. Carson, a world-renowned leader in the study of testosterone deficiency. His priceless tutelage helped me realize that men’s health in general — and Low T in particular — were mostly neglected by the wider medical community. So I honed my skills as a physician over the next 10 years by specializing in men’s sexual health, a focus few urologists choose.

These days, in my clinical practice, I take a precise, strategic approach to diagnosis and treatment — strategic in the sense of tactics that will benefit a patient’s overall health. This is labor-intensive, but it’s safer and offers better results. What does it entail?

A meticulous Low T diagnosis requires careful intelligence gathering and detailed knowledge of various testosterone tests, or “assays.” The path to a diagnosis begins with a suspicion based on patient symptoms and any visible physical manifestations. Hence the phrase “intelligence gathering”: A questionnaire or simple 10-minute office visit won’t do. What’s needed first is a long, detailed interview with the patient to uncover clues about his underlying condition.

This also entails an exhaustive review of the patient’s medical history to identify Low T risk factors: diabetes, thyroid problems, opiate use and others increase a man’s risk for a hormone deficiency. Then comes a thorough physical exam.

Once that’s all done, the next step is to validate the gathered intelligence by excluding, one by one, any causes other than testosterone deficiency that might explain the patient’s symptoms. This can be tedious, often requiring consultations with physicians in other specialties, but treating a man with testosterone when Low T isn’t what ails him can be detrimental.

Once a clear Low T picture has emerged, lab testing to confirm the diagnosis follows. This is complex stuff, and this step leads many physicians astray. To be blunt, most doctors don't understand the basics of testosterone, much less how current lab technology works, so they’re basically taking shots in the dark at this point.

A quick primer on testosterone biochemistry and transport: Testosterone is produced by the testicles and then enters the bloodstream, where some of it binds to two proteins, albumin (to which it’s bound loosely) and sex hormone binding globulin (SHBG, to which it’s bound tightly). Additionally, some testosterone remains “free” in the blood, and the combination of free and loosely bound hormone is called “bioavailable” testosterone — i.e., the functional portion of a man’s testosterone.

Accurate readings of these are critical, and an array of biochemical lab tests are available for all of these — total T, free T, bioavailable T, albumin and SHBG. Which assay should a physician choose, knowing that many labs’ accuracy often falls short? Assays used to measure free or bioavailable T are very complex and subject to misinterpretation. Ask your doctor if he knows the difference between analog, ultrafiltration and dialysis techniques for measuring free T. Deer, meet headlights.

Some clinicians, meanwhile, use albumin, SHBG and total testosterone levels to “calculate” bioavailable T, an indirect approach that can be worthwhile when more-complex assays aren’t an option. These sorts of determinations can be sensitive, though — altered binding characteristics based on age or preexisting illness can skew the results dramatically, for example — and the risk of inaccuracy is high, especially for an inexperienced physician.

Sounds maddeningly complex, no? Right you are. Accurate Low T diagnosis is elaborate, time-consuming and tricky. Trust your testosterone health to an amateur, and you might end up paying a hefty price. And that’s just to get a reliable diagnosis. Treatment, too, has its own strategic intricacies — a topic I’ll cover in a future post.